Figure 1. Timeline of the present sustained attention to response task.

Following a fixation cross of 16 s (Rest), a sequence of Japanese traffic signs was presented in random order with a fixed duration of 1 s. The sequence length was varied from 8 to 52 s with a step of 4 s. The last stimulus of the sequence was always the sign warning a traffic light ahead. Participants were instructed to press a hand-held button for each sign (Go trial) except for the last one (NoGo trial).